Treaty-Making Procedure in the United Kingdom
The power to conclude and ratify treaties in the United Kingdom is one of the few remaining prerogatives of the crown. We may search in vain for constitutional laws, provisions, and decrees specifying the required formalities incident to the negotiation, conclusion, and ratification of treaties by Great Britain, because these matters are not governed by any act of Parliament or by any written regulations. British constitutional law on these points has not been embodied in statute and rests upon the common law alone. Thus there is no express definition of the treaty-making power and no reference to the authority by whom the treaty-making power may be exercised. Nevertheless, it may be said that under British constitutional law, which in this instance is common law, the authority to make treaties is vested absolutely in the crown as the unquestioned prerogative of sovereignty.